Test Of Electrochemical Cell Experiment

Explanation
A reduction reaction is a type of chemical reaction where a compound gains electrons or hydrogen atoms, resulting in the release of oxygen. This means that oxygen is being removed or reduced from the compound. Therefore, the statement that a reduction reaction releases oxygen from a compound is true.

Explanation
A voltaic cell is a device that converts chemical energy into electrical energy through a redox reaction. It consists of two half-cells, each containing an electrode and an electrolyte solution. When connected, the chemical reactions occur at the electrodes, producing an electric current. Therefore, a voltaic cell does not require an external electric current for the occurrence of chemical reactions. Thus, the statement is false.

Explanation
The given statement is false. Reduction reactions occur at the cathode, not the anode. At the cathode, electrons are gained or reduction takes place, while at the anode, oxidation occurs where electrons are lost.

Explanation
The statement is true because a salt bridge made from agar that is added with salt KNO3 is commonly used in electrochemical cells. A salt bridge is used to maintain electrical neutrality in the cell by allowing the flow of ions between the two half-cells. Agar is a gelatinous substance that can hold the salt solution and provide a pathway for ion movement. KNO3 is a common salt used in salt bridges because it dissociates into K+ and NO3- ions, which can facilitate the flow of charge. Therefore, the statement is true.

Explanation
In the given reaction, the Zn electrode is on the left side and the Cu electrode is on the right side. According to the convention, electrons flow from the anode (Zn) to the cathode (Cu) in a galvanic cell. Therefore, the statement "electrons flow from Cu to Zn electrode" is false.

Explanation
The given equation represents a redox reaction where silver ions (Ag+) are reduced to silver (Ag) and copper ions (Cu2+) are oxidized to copper (Cu). The positive value of E°sel indicates that the reaction is spontaneous and will proceed in the forward direction. Therefore, the statement "True" is correct.

Explanation
Aluminum metal can be used as a protective iron in cathodic protection because it has a more negative electrode potential than iron. When aluminum is connected to iron in a corrosive environment, it acts as a sacrificial anode and corrodes instead of the iron. This sacrificial corrosion of aluminum protects the iron from corroding, making it an effective method of cathodic protection.

Explanation
Citrus fruits can actually be used to generate electric current because they contain electrolytes such as citric acid. When the fruit is connected to a circuit, the electrolytes allow for the flow of ions, creating a current. Therefore, the given statement is incorrect.

Explanation
Iron is more easily corroded in saltwater because saltwater contains dissolved salts that increase its electrical conductivity. This conductivity accelerates the electrochemical reactions that lead to corrosion. When iron is exposed to saltwater, it undergoes a process called galvanic corrosion, where the iron acts as the anode and the saltwater acts as the electrolyte. This process leads to the formation of rust on the iron surface. Therefore, the statement "Iron is more easily corroded in saltwater" is true.

Explanation
Iron corrosion involves the formation of Fe2O3.xH2O, which refers to hydrated iron(III) oxide. This compound is commonly known as rust and is formed when iron reacts with oxygen and water in the presence of moisture. The x in Fe2O3.xH2O represents the variable amount of water molecules that can be present in the compound. Therefore, the given statement is true.